Applying Wavefront Aberrometry to Spectacle Lens Correction

1
Applying Wavefront Aberrometry to Spectacle Lens
Correction

• Robert C. Campbell, MD
• Parkwood Eye Center, Elkin, NC
• the Essilor Study Group

The author has no financial interest in any
products mentioned herein Travel E
2
Applying Wavefront Optics to Progressive Lens
Design

• Power variations across PAL surface make it a
  very complex refracting device
• Characteristics (eg, lower and higher order
  aberrations) of the wavefront produced as light
  passes through depend on
• Lens material, thickness, dioptric power,
  curvature
• Gaze direction (near, intermediate, far,
  peripheral)

3
Fixing Lens-induced Aberrations with W.A.V. E.
Technology (Wavefront Advanced Vision
Enhancement)

• Lens-induced wavefront aberrations measured
• Lens design fine-tuned to eliminate/reduce
  aberrations that affect visual acuity and
  quality of vision
• Digital surfacing assures precise reproduction of
  the mathematically-defined three-dimensional lens
  shapes

4
Study Purpose

• To determine if a wavefront-optimized progressive
  addition lens (PAL) provides improved optical
  performance compared to a conventional PAL
• Enable spectacle lens dispensing decisions for
  presbyopes to be made based on scientific
  evidence

5
Methods

• Aberrometry comparison
• Wavefront-optimized lens Varilux? Physio
  (Essilor)
• Conventional lens Varilux? Panamic? (Essilor)
• Plano 1.67-index lenses with 2.00 D add
• Assumed pupil sizes
• Distance 6 mm, intermediate 5 mm, near 4 mm
• Data collected from identical locations on each
  lens surface for each distance zone

6
(No Transcript)
7
(No Transcript)
8
(No Transcript)
9
(No Transcript)
10
Wearer Studies Corroborate Wavefront Findings

• Subjects (N609) in a multicenter study found
  that, compared to conventional lenses, the
  wavefront-optimized lens provided
• clearly better/better vision at near (72),
  intermediate (65), and distance (67)
• 72 rated overall vision quality as clearly
  better/better with the wavefront-optimized lens
• Results from this study will be presented
  Tuesday, May 1st, in the ASCRS 2007 session
  "Keratorefractive Technology and Outcomes.

11
Conclusions

• Wavefront-optimized PAL provides larger areas of
  distortion-free viewing
• 3X less higher order aberration at distance
• Reduced amplitude of residual astigmatism with
  vertical orientation for up to a 30 wider
  intermediate field
• 10 reduction in maximum defocus at near for
  improved power control along a greater vertical
  area

12
Implications

• Wavefront technology in combination with digital
  surfacing is bringing improved PAL designs to
  market
• Better optics equal happier patients
• Ophthalmologists are uniquely positioned to
  understand the benefits of a wavefront-optimized
  refracting surface
• MDs can help presbyopes migrate to improved PAL
  designs